Orateur
Description
Baryon acoustic oscillation measurements by the Dark Energy Spectroscopic Instrument (Data Release 1) have revealed exciting results that show evidence for dynamical dark energy at around 3sigma when combined with cosmic microwave background and type Ia supernova observations. These measurements are based on the w0waCDM model of dark energy. The evidence is less in other dark energy models such as the wCDM model. To avoid imposing a dark energy model, we reconstruct the distance measures and the equation of the state of dark energy independent of any dark energy model and driven only by observational data. To this end, we use both single-task and multi-task Gaussian Process regression. Our results show that the model-agnostic evidence for dynamical dark energy from DESI is much less than when imposing the w0waCDM model. Our analysis also provides model-independent constraints on cosmological parameters such as the Hubble constant and the matter-energy density parameter at present. We find that the reconstructed values of these parameters are inconsistent with the results reported in DESI with the w0waCDM model. However, they are almost consistent with DESI for the wCDM model.
